Mobile platforms offer increasingly sophisticated capabilities associated with the motion and/or position location sensing of the mobile platform. New software applications, such as, for example, those related to personal productivity, collaborative communications, social networking, and/or data acquisition, may utilize motion and/or position sensors to provide new features and services to consumers.
Such motion and/or position determination capabilities may be provided using Satellite Positioning Systems (SPS), such as a global positioning system (GPS). GPS can provide absolute positioning with accuracies on the order of a few meters in open sky conditions. However, the performance of GPS drastically degrades if large parts of the sky are obstructed. This occurs, for example, in so-called urban canyon scenarios, where the GPS receiver may be located in an area with one or more tall buildings. In these urban canyon scenarios GPS positions may be off by as much as 50 m. These large positioning errors are prohibitive in applications such as vehicular automation (i.e., Advanced Driver Assistance Systems—ADAS) and robotics (e.g., drone positioning and navigation). The large positioning errors in urban canyons are mainly caused by non-line-of-sight (NLOS) observations. Such observations result when the line-of-sight (LOS) path from an SPS receiver to a satellite is blocked by nearby obstacles, such tall buildings. In such situations, the SPS receiver may erroneously track a reflected version of the satellite signal (i.e., NLOS) rather than tracking the satellite signal directly (i.e., LOS). Urban canyon scenarios are challenging because many of the GPS measurements at a particular time epoch may actually be such erroneous NLOS measurements.